Vapor electric discharge device



Aug. 1, 1933. c. KRAMER 1,920,753

VAPOR ELECTRIC DISCHARGE DEVICE Filed April 15, 1930 Inventor: ChristianKTT'EU'TIQT} His Attorncf Patented Aug. 1, 1933 t vsroa nrsc'raicDISCHARGE DEVICE Christian Kramer, Berlin-Pankcw, Germany, assignor toGeneral Electric (Company, a Corporation of New York Application April15, 1930, Serial No. 444,568, and

in Germany July 24, 1929 4 Claims. (Cl. 250-275) My invention relates toelectric discharge devices, such as mercury arc rectifiers or the like,and has for its principal object the provision of an improved means forreducing the number of 5 back-ignitions produced in such rectifier-sduring operation.

High power rectifiers are sometimes provided with one, and sometimeswith several suction apertures in order to remove residual gases mevolved in the course of operation. A good vacuum may be thus obtained,but back-ignitions are frequently produced because the stream of mercuryvapor rising from the cathode prevents, in certain circumstances, theresidual gases from rising and being removed from the vicinity of theanodes.

The number of back ignitions is greatly reduced by the presentinvention, according to which the container of the rectifier is dividedby a cowl into two concentric chambers which are separately exhausted.

My invention will be better understood from the following descriptionwhen considered in connectionvwith the accompanying drawing, and itsscope will be pointed out in the appended claims.

Referring to the drawing, the single figure illustrates a mercury arcrectifierconstructed in accordance with my invention.

Referring to the drawing, the container g of the rectifier is closed byan upper cover d traversed in the usual way by the leads of the anodesa. A water-cooled cowl h is fitted to the centre of the said upper coverof the rectifier, the upper portion of the cowl leading to a vacuum pumpin through the suction pipe 81. The chamber which concentricallysurrounds the cowl h and in which the anodes are located, is incommunication with another suction pipe 82 connected to a second vacuumpump 792. When the rectifier is under high load, the bulk of the risingstream of mercury vapor from the cathode 7c is intercepted by the cowlh; the mercury condenses and the residual gases thus released flow tothe suction pipe 81. The stream of mercury vapor produces acomparatively high pressure in this chamber; this pressure has howeverno detrimental effect upon the anodes and in certain circumstances mayeven assist, due to its pumping action, the removal oi gases therefrom.The pressure in the outer anode chamber is therefore lower than in thecowl.

The residual gases flowing from the anode-protecting cylinders areremoved by the vacuum pump 112 through the suction pipe 82.

The main stream of vapor flows without eddies from the cathode, into thecowl, so that the residual gases may leave the anode-protecting cylinderunimpeded through the lower portion thereof. A further advantageconsists in that the high density of vapor produced at the cathodecannot spread and as a result a low density of vapor, free fromextraneous gases and improving the operation of the rectifier, may bemaintained in the anode chamber.

The hollow water-cooled cowl may be replaced by a solid cowl ofsheet-metal the inner and outer faces of which may be used as supportsfor cooling coils.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. An electric discharge device including a container, an anodesupported by a wall of said container, a cowl supported by said wall anddividing said container into two concentric chambers separate from eachother at the upper portions thereof, two separate evacuating means toexhaust said chambers separately, one of said evacuating means openinginto said cowl at a point therein in the upper portion thereof, theother of said evacuatingmeans opening into said container at a pointtherein outside said cowl and in the upper portion of the outer of saidconcentric chambers. v

2. An electric discharge device including a container, a cowl supportedby a wall of said container and dividing said container into twoconcentric chambers separate from each other at the upper portion ofsaid container, an anode supported on said wall between said cowl andanother wall of said container, and two separate evacuating means toexhaust said chambers sep- 0 arately, said two evacuating means openingrespectively into said cowl in the upper portion thereof and into theupper portion of the space constituting the outer of said concentricchambers between said cowl and said other wall.

3. An electric discharge device including a con-= tainer, a cowlsupported by a wall of said container and dividing said container intotwo concentric chambers separate from each other at the upper portion ofsaid container, an anode supcentric chanibersseparate from eachotheratthe upper portion of said container, an anode supported on saidwall between said cowl :.and:another wall 'of said container, twoseparate evacuating means .to exhaust said chambers separately, said twocevacuating means opening respectively into said'cowl in the upperportion thereof and into the upper portion of "the space constitutingthe outer of said concentric chambers between said cowland said otherwall, and means for cooling said cowl.

CHRISTIAN KRKMER.

